Containment reinforced flywheel

ABSTRACT

An inertial energy storage rotor having a reinforcement harness encompassing its outer circumference and sides, and having improved adjustable tensioning spoke elements extending from said harness and attaches to flywheel hub. The adjustable tensioning spokes allow the harness to be evenly torqued around the perimeter and sides of the rotor to provide additional reinforcement allowing the rotor to withstand centrifugal forces higher than otherwise able.

TECHNICAL FIELD

The present invention relates to an inertia flywheel and its capacity tostore electrical energy as kinetic energy and to recover electricalenergy from the stored kinetic energy.

BACKGROUND OF INVENTION

The flywheel has long been used to store energy. It is a relativelysimple device from which it is possible to store and retrieve energyreadily, either by mechanical means or by using electric motors andgenerators. Attempts have been made to maximize the rotational inertiaof the flywheel, thereby increasing the flywheel's energy storagecapability by placing as much mass as possible at the outer portion ofthe radius or rotor. The more mass or weight of rim material required bythe intended use of the flywheel, the more rigidity or strength isrequired to meet the loads without self-destruction of the flywheel. Thepresent invention provides an inertia flywheel comprising a rotorcontained within a partial wrap harness of suitable material terminatingin a series of adjustable strap tensioners attached to a hub with asuitable tensioning nut or similar device. A wheel and axle aretypically connected with spokes and/or a rim. Unlike the spokes of awagon wheel that hold the rim away from the hub, the present inventionoperates similar to a bicycle or motorcycle wheel where the spokes aretensioned and torqued to pull the rim of the wheel toward the hub. Thepresent invention creates additional strength by tensioning (pulling)the rotor toward the hub, allowing for the use of much heavier materialsin the rotor and much lighter materials in the wrap harness, straptensioners and hub. In a preferred embodiment, the rotor is liquidfilled and includes suitable one-way valves such as the Variable InertiaFlywheel of U.S. patent application Ser. No. 11/833,611.

SUMMARY OF THE INVENTION

The containment-reinforced flywheel is a simple device designed toincrease a flywheels energy storage capability by placing as much massas possible at the outer portion of the radius (rotor). The containmentportion of the present invention is a combination of a harness, straps,tensioners and hub designed to support the rotor when at rest andcontain the rotor when rotating at a desired speed and at a desiredradius while maximizing the ratio of rotor mass to the mass of thecontainment portion.

The containment portion of the present invention is a simple,lightweight containment where the outer harness wraps around andsupports the entire outer circumference of the rotor. At desiredintervals, a plurality of evenly spaced straps taper from the outerharness to adjustable tensioners attached to a hub.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a partial lateral view of the flywheel rotor inside thecontainment portion.

FIG. 2 shows a sectional view of the rotor inside the containmentportion at a location through the strap along a line A-A in FIG. 1.

FIG. 3 shows a sectional view of the rotor inside the containmentportion at a location between straps along a line B-B in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The containment portion of the present invention comprises an outerharness 1 that wraps around and supports the entire circumference of theflywheel rotor 5. At desired intervals, evenly spaced straps 2 taperfrom both sides of the outer harness 1 to adjustable tensioners 3attached to the hub 4. The hub 4 is attached to an axle 6 or can rotatefreely on a bearing around the axle 6. The adjustable tensioners 3function in a manner similar to that of the spokes of a bicycle wheel,and can be torqued to draw the outer harness 1 tightly to the hub 4 thuscontaining the flywheel rotor 5. Optionally, the orientation of thetensioners 3 can be such that each strap 2 on each side of the flywheelrotor 5 has a separate tensioner 3 attached to the hub 4.

The straps 2 and harness 1 which comprise the containment portion of thepresent invention may be constructed of light weight materials such assheet metal, stainless steel, titanium, polymeric materials, or othermaterials having the strength to contain a rotor which is spinning atthe rotational speed required by the intended use of the flywheel whilenot adding unnecessary weight to the combination. The harness 1surrounds the front edge and sides of the rotor 5. The straps 2 connectthe harness 1 to the adjustable tensioners 3 that are positioned atintervals around hub 4.

The flywheel of the present invention comprises a rotor 5 which may beeither solid or hollow, and which is drawn to the hub by the tensioningstraps of the containment portion of the device. In a preferredembodiment, the flywheel rotor 5 is a hollow circular tube constructedof steel, titanium, or other metallic material; composite materials;rubber; or other materials suitable to withstand the loads and stressesof the intended use of the flywheel, but light enough to not addunnecessary weight to the combination. The interior of the flywheelrotor 5 preferably is filled with a non-corrosive liquid such as wateras described in U.S. patent application Ser. No. 11/833,611 and referredto as a Variable Inertia Flywheel. The “fill ratio”, that is the ratioof the fluid mass to the structural mass, determines the performance ofthe flywheel.

For example, a flywheel with a fill ratio of 80% spins up five timesfaster and stores energy 25 times faster than a conventional flywheel ofthe same weight and diameter. Thus the high fill ratios obtainable withthe containment flywheel of the present invention result in faster spinup times and faster energy storage. Flywheel rotor 5 is mounted on axle6 at outer hub 4.

What is claimed is:
 1. An internal energy storage rotor including acentral hub, the storage rotor comprising: (a) an outer harness (1)which encompasses the entire outer circumference and sides of said rotor(5); (b) a plurality of straps (2) distributed from both sides of saidharness; (c) a plurality of adjustable tensioners (3) connecting saidstraps to a central hub (4); (d) the outer harness, straps andadjustable tensioners are each made from a material selected from agroup consisting of sheet metal, stainless steel, titanium, or polymericmaterial; whereby adjustable tensioners allow outer harness to be evenlytorqued from hub to outer perimeter of rotor.
 2. A method ofconstructing a flywheel comprising: (a) providing an outer harness (1)which encompasses the entire outer circumference and sides of a rotor(5); (b) providing a plurality of straps (2) distributed from both sidesof said harness; (c) providing a plurality of adjustable tensioners (3)connecting said straps to a central hub (4); (d) the outer harness,straps and adjustable tensioners are each made from a material selectedfrom a group consisting of sheet metal, stainless steel, titanium, orpolymeric material; whereby adjustable tensioners allow outer harness tobe evenly torqued from hub to outer perimeter of rotor.